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| author | Segher Boessenkool <segher@gcc.gnu.org> | 2018-07-26 12:16:48 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2018-07-26 12:16:48 +0200 |
| commit | 328aa7876732da9bbf851f7b9309b1f6fda1cd9d (patch) | |
| tree | c7dcf974de0227370ede0f4f56a783a580a95da1 | |
| parent | 977667e6b74a56db3747caaed8ba776f6cae8cdf (diff) | |
| download | gcc-328aa7876732da9bbf851f7b9309b1f6fda1cd9d.zip gcc-328aa7876732da9bbf851f7b9309b1f6fda1cd9d.tar.gz gcc-328aa7876732da9bbf851f7b9309b1f6fda1cd9d.tar.bz2 | |
combine: Another hard register problem (PR85805)
The current code in reg_nonzero_bits_for_combine allows using the
reg_stat info when last_set_mode is a different integer mode. This is
completely wrong for non-pseudos. For example, as in the PR, a value
in a DImode hard register is set by eight writes to its constituent
QImode parts. The value written to the DImode is not the same as that
written to the lowest-numbered QImode!
PR rtl-optimization/85805
* combine.c (reg_nonzero_bits_for_combine): Only use the last set
value for hard registers if that was written in the same mode.
From-SVN: r262994
| -rw-r--r-- | gcc/ChangeLog | 10 | ||||
| -rw-r--r-- | gcc/combine.c | 3 |
2 files changed, 10 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7a66a63..3518ecf 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,8 +1,14 @@ +2018-07-26 Segher Boessenkool <segher@kernel.crashing.org> + + PR rtl-optimization/85805 + * combine.c (reg_nonzero_bits_for_combine): Only use the last set + value for hard registers if that was written in the same mode. + 2018-07-26 Martin Liska <mliska@suse.cz> - PR gcov-profile/86536 + PR gcov-profile/86536 * gcov.c (format_gcov): Use printf format %.*f directly - and do not handle special values. + and do not handle special values. 2018-07-25 Claudiu Zissulescu <claziss@synopsys.com> diff --git a/gcc/combine.c b/gcc/combine.c index cfe0f19..8f6db4f 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10169,7 +10169,8 @@ reg_nonzero_bits_for_combine (const_rtx x, scalar_int_mode xmode, rsp = ®_stat[REGNO (x)]; if (rsp->last_set_value != 0 && (rsp->last_set_mode == mode - || (GET_MODE_CLASS (rsp->last_set_mode) == MODE_INT + || (REGNO (x) >= FIRST_PSEUDO_REGISTER + && GET_MODE_CLASS (rsp->last_set_mode) == MODE_INT && GET_MODE_CLASS (mode) == MODE_INT)) && ((rsp->last_set_label >= label_tick_ebb_start && rsp->last_set_label < label_tick) |